The present invention relates to a deburring tool and, more particularly, to a deburring tool and method for deburring a hole that extends entirely through a workpiece.
When deburring edges of a hole that extends through a workpiece where a distal edge of the hole is disposed on an opposite side of the workpiece from the deburring tool, or when attempting to simultaneously debur both distal and proximal edges of a hole that extends through a workpiece, it is common to use a deburring tool having one or two enlarged ends with deburring cutter members on at least a distal one of the enlarged ends, and an intermediate member having a smaller diameter than the enlarged end at the distal end of the deburring tool. The deburring tool is moved in a circular path around the hole with the intention that at least the deburring cutter members on the enlarged distal end of the deburring tool will debur the distal edge of the hole. The intention is that the longitudinal axis of the deburring tool will remain straight as the deburring operation occurs. U.S. Pat. No. 7,278,806 discloses a deburring tool of this type. The reality, however, is that the deburring tool will often bend as a result of the forces to the tool, and this may interfere with deburring the distal edge of the hole.
It is desirable to provide a deburring tool and method that can debur a distal hole edge and/or two hole edges while minimizing problems associated with bending of the deburring tool.
According to an aspect of the present invention, a deburring tool includes a shank attachable at a first end to a chuck and a working portion at a second end of the shank. The working portion includes a first end portion closest to and joining the second end of the shank at a first end of the first end portion, a second end portion furthest from the shank, and an intermediate portion between the first end portion and the second end portion, a first end of the intermediate portion joining a second end of the first end portion and a second end of the intermediate portion joining a first end of the second end portion. The intermediate portion tapers continuously from a largest diameter at the first end of the intermediate portion to a smallest diameter at the second end of the intermediate portion, at least part of the second end portion has a larger diameter than the second end of the intermediate portion, and deburring cutter members are provided on the second end portion adjacent the second end of the intermediate portion.
According to another aspect of the present invention, a method of deburring a hole extending from a first surface to a second surface of a workpiece using the deburring tool includes extending the working portion of the deburring tool through the hole so that the first end portion contacts the first surface of the workpiece, rotating the deburring tool about a longitudinal axis thereof and deburring the hole adjacent the second surface of the workpiece with the deburring cutters on the second end portion, and, while rotating the deburring tool about the longitudinal axis thereof, pivoting the deburring tool in a circular fashion so that the second end portion of the deburring tool moves in a circular path and the first end portion of the deburring tool and the first surface of the workpiece define a fulcrum.